// Copyright © 2015, 2017, Oracle and/or its affiliates. All rights reserved.
//
// This program is free software; you can redistribute it and/or modify
// it under the terms of the GNU General Public License, version 2.0, as
// published by the Free Software Foundation.
//
// This program is also distributed with certain software (including
// but not limited to OpenSSL) that is licensed under separate terms,
// as designated in a particular file or component or in included license
// documentation.  The authors of MySQL hereby grant you an
// additional permission to link the program and your derivative works
// with the separately licensed software that they have included with
// MySQL.
//
// Without limiting anything contained in the foregoing, this file,
// which is part of MySQL Connector/NET, is also subject to the
// Universal FOSS Exception, version 1.0, a copy of which can be found at
// http://oss.oracle.com/licenses/universal-foss-exception.
//
// This program is distributed in the hope that it will be useful, but
// WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
// See the GNU General Public License, version 2.0, for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program; if not, write to the Free Software Foundation, Inc.,
// 51 Franklin St, Fifth Floor, Boston, MA 02110-1301  USA

using System;
using System.Diagnostics;
using System.Reflection;

namespace MySql.Data.EntityFrameworkCore.Utils
{
  [DebuggerStepThrough]
  internal static class SharedTypeExtensions
  {
    public static Type UnwrapNullableType(this Type type) => Nullable.GetUnderlyingType(type) ?? type;

    public static bool IsNullableType(this Type type)
    {
      var typeInfo = type.GetTypeInfo();

      return !typeInfo.IsValueType
             || (typeInfo.IsGenericType
                 && typeInfo.GetGenericTypeDefinition() == typeof(Nullable<>));
    }

    public static bool IsInteger(this Type type)
    {
      type = type.UnwrapNullableType();

      return type == typeof(int)
             || type == typeof(long)
             || type == typeof(short)
             || type == typeof(byte)
             || type == typeof(uint)
             || type == typeof(ulong)
             || type == typeof(ushort)
             || type == typeof(sbyte)
             || type == typeof(char);
    }

    public static bool CanBeAutoIncrement(this Type type)
    {
      return IsInteger(type)
        || type == typeof(float)
        || type == typeof(double);
    }
  }
}
